These computed molecular parameters, including dipole moment, polarizability, proton affinity, and ionization energy of volatile organic compounds (VOCs), are crucial for the identification and quantification of VOCs in chemical ionization mass spectrometry. These parameters are determined using Density Functional Theory (DFT) methods implemented in software such as Gaussian and Quantum ESPRESSO. The electric dipole moment and polarizability of neutral molecules are fundamental in calculating the rate coefficients of ion-molecule reactions through collision-based models. Similarly, proton affinity is key to assessing the feasibility of proton transfer from a reagent ion to the neutral molecule in potential proton transfer reactions, typically involving H3O+ or NH4+ ions in mass spectrometry. Ionization energy, on the other hand, determines the likelihood of charge transfer from NO+ or O2+ ions to a neutral molecule.

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The table below shows DFT computed values of molecular properties of VOCs related to food and beverages.

Sr. no	CAS no.	Molecule Name	Mass (a u)	Dipole Moment (Debye)	Polarizability (ų)	Proton Affinity (Kcal/mol)	Ionization Energy (eV)
1	87-40-1	2,4,6-trichloroanisole	211.47	1.5713	18.3618	183.51	8.87
2	607-99-8	2,4,6-tribromoanisole	344.83	1.5411	22.1138	186.17	8.67
3	87-86-5	Pentachlorophenol	266.34	1.7846	20.3273	167.15	8.76
4	608-71-9	Pentabromophenol	488.59	1.545	26.1441	174.17	8.75
5	88-06-2	2,4,6-trichlorophenol	197.45	1.4664	16.5319	174.35	9.03
6	118-79-6	2,4,6-tribromophenol	330.8	1.4027	20.2875	178.56	8.81
7	54135-80-7	2,3,4-trichloroanisole	211.47	4.4211	18.384	181.32	8.36
8	50375-10-5	2,3,6-trichloroanisole	211.47	1.9058	18.2082	183.87	8.83
9	938-86-3	2,3,4,5-tetrachloroanisole	245.91	3.7542	20.4157	178.4	8.44
10	938-22-7	2,3,4,6-tetrachloroanisole	245.91	2.004	20.2719	181.96	8.85
11	6936-40-9	2,3,5,6-tetrachloroanisole	245.91	1.6095	20.279	181.49	8.85
12	553-82-2	2,4-dichloroanisole	177.03	3.3959	16.5512	182.77	8.26
13	1984-65-2	2,6-dichloroanisole	177.03	2.0445	16.2137	186.69	8.96
14	65767-22-8	Cis-1,5-octadien-3-one	124.18	3.0161	15.2005	211.13	8.7
15	50306-18-8	Cis-1,5-octadien-3-ol	126.2	1.9952	15.6403	200.87	8.72
16	3391-86-4	1-octene-3-ol	128.22	1.4363	15.3933	197.68	9.37
17	4312-99-6	1-octene-3-one	126.2	3.1576	14.6985	203.94	9.23
18	124-13-0	Octanal	128.21	3.3329	14.845	192.82	9.38
19	24168-70-5	2-sec-butyl-3-methoxypyrazine	166.22	1.3297	18.4263	215.84	8.53
20	24683-00-9	3-isobutyl-2-methoxypyrazine	166.22	1.4137	18.3829	215.77	8.51
21	25773-40-4	2-isopropyl-3-methoxypyrazine	152.19	1.3783	16.7422	215.39	8.56
22	92508-08-2	2-methoxy-3,5-dimethylpyrazine	138.17	1.1254	15.103	217.16	8.32
23	2371-42-8	2-methylisoborneol	168.28	1.5298	18.7068	217.79	9.21
24	19700-21-1	Geosmin	182.31	1.4274	20.2848	205.05	8.86
25	90-05-1	Guaiacol	124.14	2.8711	13.2576	191.5	7.91
26	2785-89-9	4-ethylguaiacol	152.19	1.1898	17.1949	198.28	7.55
27	0123-07-09	4-ethylphenol	122.16	1.4494	14.4601	182.32	8.07
28	470-82-6	Eucalyptol (1,8-cineole)	154.25	1.5507	17.014	213.24	8.46
29	1124-39-6	4-ethylcatechol	138.17	2.3752	15.1428	198.28	7.85
30	93-51-6	4-methylguaiacol	138.17	1.2064	15.3233	195.18	7.58
31	18374-76-0	Rotundone	218.34	3.9682	26.1015	219.7	8.36
32	106-24-1	Geraniol	154.25	2.4482	19.4274	212.37	8.1
33	53834-70-1	Hotrienol	152.24	1.7387	19.8334	208.05	7.99
34	78-70-6	Linalool	154.25	1.9302	18.932	214.27	8.38
35	106-25-2	Nerol	154.25	2.6397	18.6116	209.87	8.37
36	98-55-5	α-terpineol	154.25	1.6648	17.9833	200.56	8.23
37	120-72-9	Indole	117.15	2.1599	14.7231	199.49	7.66
38	603-76-9	1-methylindole	131.18	2.4849	16.7336	203.64	7.44
39	551-93-9	2-aminoacetophenone	135.16	1.9619	16.0802	214.57	7.74
40	87-64-9	2-chloro-6-methylphenol	142.58	0.8785	14.367	177.47	8.41
41	106-68-3	3-octanone	128.21	2.7427	14.5962	203.37	9.12
42	1195-79-5	Fenchone	152.23	3.097	16.6014	207.11	8.55
43	1632-73-1	Fenchol	154.25	1.4622	17.0469	198.48	9.15
44	18409-17-1	Trans-2-octen-1-ol	128.21	1.737	15.5912	203.08	8.94
45	1825-21-4	Pentachloroanisole	280.35	2.1192	22.2201	180.35	8.95
46	7783-06-04	Hydrogen Sulfide	34.08	0.99	3.71	169.1	10.4
47	74-93-1	Methanethiol	48.11	1.56	5.55	186.1	9.4
48	1975-08-01	Ethanethiol	62.14	1.68	7.43	190.6	9.2
49	75-18-3	Dimethyl Sulfide	62.14	1.6	7.46	199.3	8.6
50	352-93-2	Diethyl Sulfide	90.19	1.64	11.34	206.3	8.3
51	624-92-0	Dimethyl Disulfide	94.2	2.03	10.79	193.7	8.1
52	110-81-6	Diethyl Disulfide	122.3	2.15	14.67	197.8	7.9
53	1534-08-03	Methyl thioacetate	90.15	1.36	9.64	198.5	9.1
54	51755-83-0	3-Mercaptohexan-1-ol	134.24	1.68	15.43	196.6	8.6
55	19872-52-7	4-Mercapto-4-methylpentan-2-one	132.23	2.27	14.86	198.2	8.5
56	255391-65-2	4-Mercapto-4-methylpentan-2-ol	134.24	2.53	15.34	204.7	8.5
57	95-16-9	Benzothiazole	135.19	1.34	15.91	220.7	8.6
58	1998-02-02	2-Furanmethanethiol	114.17	1.94	12.81	199.1	8.1
59	60-24-2	2-mercaptoethanol	78.14	2.5	8.14	193.4	9
60	100-53-8	Benzenemethanethiol	124.21	1.48	15.74	195.3	8.3
61	5862-40-8	2-mercaptoethyl-acetate	120.17	1.83	11.91	199.2	9.1
62	26473-61-0	3-mercaptopropyl-acetate	134.2	1.61	13.97	199.6	9
63	75100-46-8	cis-3,6-dimethyl-1,2,4,5-tetrathiane	184.4	0	19.83	196.1	8
64	5287-45-6	prenyl-mercaptan	102.2	1.78	13.35	198.2	8.1
65	75100-47-9	trans-3,6-dimethyl1,2,4,5-tetrathiane	184.4	0	19.11	195.3	8.3
66	28588-74-1	2-Methyl-3-furanthiol	114.17	0.9	12.47	190.3	7.7
67	149834-43-5	2-methylthiolane-3-ol	118.2	2.12	12.71	207.5	8.2
68	34300-94-2	3-Mercapto-3-methylbutan-1-ol	120.22	1.84	13.52	197.7	8.6
69	5466-06-08	ethyl-3-mercaptopropionate	134.2	2.76	13.91	196.7	8.9
70	137-00-8	5-2-hydroxyethyl-4-methylthiazole	143.21	2.79	15.29	229.7	8.1
71	13679-85-1	2-Methyltetrahydrothiophen-3-one	116.18	1.72	12.14	196.1	8.6
72	0505-10-02	3-Methylsulfanylpropan-1-ol	106.19	3.06	12.03	203.1	8.4
73	136954-20-6	3-Mercaptohexylacatate	176.28	1.47	19.32	194.9	8.8
74	625-60-5	ethylthioacetate	104.17	1.41	11.57	201.2	9
75	109-08-0	2-methylpyrazine	94.11	0.65	10.32	216.52	9.25
76	13925-00-3	2-ethylpyrazine	108.14	0.72	12.15	217.64	9.17
77	13925-07-0	2-ethyl-3,5-dimethylpyrazine	136.19	0.57	16.07	225.65	8.74
78	108-50-9	2,6-dimethylpyrazine	108.14	0.72	12.24	221.09	9.26
79	123-32-0	2,5-dimethylpyrazine	108.14	0	12.34	220.38	9.21
80	14667-55-1	2,3,5-trimethylpyrazine	122.17	0.65	14.23	224.76	8.88
81	1124-11-09	2,3,5,6-tetramethylpyrazine	136.19	0	16.18	228.09	8.53
82	106-98-9	1-butene	56.11	0.35	7.52		
83	78-79-5	isoprene	68.12	0.25	10.22		
84	108-88-3	toluene	92.14	0.34	12.9		
85	75-07-0	acetaldehyde	44.05	2.65	4.3		
86	64-17-5	ethanol	46.07	1.53	4.53		
87	67-64-1	acetone	58.08	2.29	6.09		
88	123-38-6	propanal	58.08	2.75	6.13		
89	108-95-2	phenol	94.11	1.34	11.73		
90	2043-61-0	cyclohexanal	112.17	1.51	11.32		
91	100-52-7	Benzaldehyde	106.12	3.28	10.06		
92	106-36-5	propyl propanoate	116.16	1.79	14.2		
93	105-54-4	ethylbutanoate	116.16	1.74	14.2		
94	109-21-7	butyl butanoate	144.21	2.12	17.2		
95	107-92-6	N-butyric acid	88.11	1.8	10		
96	513-86-0	3-hydroxybutanone	88.11	2.6	8.8		
97	557-31-3	allyl ethyl ether	86.13	1.2	10.7		
98	127-17-3	pyruvic acid	88.06	2.3	6.6		
99	97-53-0	eugenol	164.2	2.5	19.3		
100	103-26-4	methyl cinnamate	162.18	1.9	19.2		
101	119-61-9	Benzophenone	182.22	3.23	22.75	216.25	8.68
102	22583-75-1	Benzophenone-d10	192.28	3.23	22.75	216.38	8.68
103	1137-42-4	4-hydroxybenzophenone	198.22	2.48	23.95	219.52	8.37
104	25913-05-7	4-fluoro-4hydroxybenzophenone	216.21	3.95	23.97	218.41	8.58
105	131-58-8	2-methylbenzophenone	196.24	3.37	24.27	216.94	8.56
106	117-99-7	2-hydroxybenzophenone	198.22	4.26	23.39	218.57	8.39
107	643-65-2	3-methylbenzophenone	196.24	3.62	24.73	217.95	8.51
108	134-84-9	4-methylbenzophenone	196.24	3.53	25.08	219.67	8.49
109	2128-93-0	4-phenylbenzophenone	258.3	3.32	33.22	225.52	8.55
110	131-57-7	2-hydroxy-4-methoxybenzophenone	228.24	4.29	26.74	191.45	8.05
111	606-28-0	methyl-2-benzoylbenzoate	240.25	4.46	27.04	216.81	8.63
112	1143-72-2	2,3,4-trihydroxybenzophenone	230.22	4.49	25.13	186.24	8.13
113	131-53-3	2,2-dihydroxy-4-methoxybenzophenone	244.24	5.59	27.35	217.36	7.88
114	85-19-8	5-chloro-2-hydroxybenzophenone	232.66	2.41	25.91	211.88	8.33
115	84-66-2	diethyl phthalate	222.24	3.67	23.16	202.56	9.05
116	120-51-4	benzyl benzoate	212.24	2.34	25.05	205.94	8.87
117	84-69-5	disobutyl phthalate	278.34	3.82	30.49	204.78	8.99
118	84-74-2	dibutyl phthalate	278.34	3.96	30.17	204.61	9.03
119	117-82-8	bis (2-methoxyethyl) phthalate	282.29	4.9	28.19	220.65	8.68
120	605-54-9	bis (2-ethoxyethyl) phthalate	310.34	3.85	31.98	209.44	8.56
121	131-11-3	dimethyl phthalate	194.18	3.38	19.42	199.15	9.16
122	947-19-3	1-Hydroxycyclohexyl Phenyl Ketone	204.26	1.4	22.88	208.53	8.65
123	525-82-6	Flavone	222.24	4.49	28.11	226.91	8.28
124	131-18-0	dipentyl phthalate	306.4	3.79	33.74	204.59	9.01
125	85-68-7	benzyl butyl phthalate	312.4	3.87	35.31	205.19	8.6
126	84-63-9	Bis (4-methyl-2-pentyl) phthalate	334.4	0.84	37.36	213.97	8.9
127	84-75-3	Di-n-hexyl phthalate	334.4	3.92	37.61	217.23	9.11
128	117-83-9	Bis (2-n-butoxyethyl) phthalate	366.4	3.24	39.74	224.77	8.58
129	84-61-7	dicyclohexyl phthalate	330.4	3.66	35.99	213.13	8.85
130	117-81-7	di(2-ethylhexyl) phthalate	390.6	4.91	44.47	217.94	8.88

DFT computed molecular parameters

DFT computed molecular parameters

The values computed using Density Functional Theory (DFT) methods provided herein serve as valuable references, particularly in situations where experimental values are unavailable. For the most comprehensive list of molecules and the most current updates on these parameters, please refer to our continuously updated repository. When incorporating this work into your research or publications, please ensure proper citation as per the references provided below.

References

• Manjeet Bhatia, Franco Biasioli, Luca Cappellin, Paolo Piseri, Nicola Manini, Abinitio calculation of the proton transfer reaction rate coefficients to volatile organic compounds related to cork-taint in wine, Journal of Mass Spectrometry, 55(11), e4592, 2020.
• Manjeet Bhatia, Nicola Manini, Franco Biasioli, Luca Cappellin, Calculated Rate Coefficients Between CI-MS Reagent Ions and Organosulfur Compounds Causing Food Taints and Off-flavours, International Journal of Mass Spectrometry, 478, 116860 2022.
• Manjeet Bhatia, Integrating DFT and CI-MS Techniques to Assess Benzophenone Derivatives in Food Packaging: Implications for Enhancing Food Quality and Safety, 2024., Journal of mass spectrometry , 06 March 2024.
• Manjeet Bhatia, Computational Insights into Phthalate Ester-Linked VOCs: A DFT-Based Approach for CI-MS Analysis, Rapid Communications in Mass Spectrometry , 2024.